1. Field of the Invention
The present invention relates to a timing controller that receives image data from a graphic controller or other devices, and that transmits information to a gate driver or a source driver.
2. Description of the Related Art
FIG. 1 is a block diagram showing an image display system. An image display system 100R includes a display panel 102 configured as a liquid crystal panel, an organic EL panel or the like, a gate driver 104, a source driver 106, a graphic controller 110, and a timing controller 200R. The graphic controller 110 generates image data to be displayed on the display panel 102. The image data includes pixel (RGB) data in the form of serial data, which is transmitted to the timing controller 200R.
The timing controller 200R receives the image data, and generates various kinds of control signals and timing signals (synchronization signals). The gate driver 104 sequentially switches the selected scanning line from among the scanning lines LS of the display panel 102 in synchronization with a signal received from the timing controller 200R. Furthermore, the RGB data is supplied to the source driver 106.
Typically, the timing controller 200R and the graphic controller 110 are coupled via a differential serial interface. Before a link is established via the serial interface between the timing controller 200R and the graphic controller 110, image data transmission cannot be performed after the image display system 100R is started up. Accordingly, in this period of time, the display panel 102 cannot display an image. Also, if link disconnection occurs due to noise or the like after the link has been established, the display panel 102 cannot display an image before the link is established again.
Also, if a corresponding cable is unplugged or disconnected, or otherwise if a malfunction occurs in a part of the serial interface or the graphic controller 110, the same problem occurs. In the present specification, such a problem state in which an image display operation cannot be performed will be referred to as the “display inoperative state”.
With conventional techniques, in some cases, the timing controller 200R is provided with an implemented function for displaying given information on the display panel 102 in the display inoperative state. For example, the timing controller 200R stores a predetermined failsafe display pattern 201. Examples of such a display pattern 201 includes a color bar image, a monotone screen image, and the like. With such an arrangement, in the display inoperative state, the timing controller 200R transmits such a failsafe display pattern 201 to the source driver 106 as a substitution for the image data to be received from the graphic controller 110.
As a result of investigating such an image display system 100R shown in FIG. 1, the present inventor has come to recognize the following problem. The image display system 100R shown in FIG. 1 is capable of preventing the occurrence of an complete blackout state in the display panel 102 even in the display inoperative state. However, the pattern 201 to be displayed in this state is required to be determined in a design stage for the image display system 100R. That is to say, such an arrangement is not capable of displaying useful information in a real-time manner.